1. Technical Field
The present disclosure relates to a nonaqueous electrolyte secondary battery.
2. Related Art
As a nonaqueous electrolyte secondary battery, for example, a lithium ion secondary battery has been known. In the lithium ion secondary battery, a power generating element including a positive electrode plate in which a lithium composite oxide or the like is used as an active material, a negative electrode plate in which a carbon material or the like (such as graphite) is used as an active material, and a plurality of stacked separators, and an electrolyte containing lithium salt or the like (such as a nonaqueous electrolyte having lithium salt or the like dissolved therein) are housed in an exterior body such as a laminate film. It has been known that the structure of an electrode is roughly classified into a wound type and a stacked type. The wound type includes a rectangular positive electrode plate and a negative electrode plate, which are wound with a separator interposed therebetween. The stacked type includes a plurality of sheet-like positive electrode plates and negative electrode plates stacked alternately with a separator interposed therebetween. The positive electrodes and the negative electrodes integrated to extract current from the sheets are respectively connected to a positive electrode terminal and a negative electrode terminal as external terminals. The stacked type is advantageous as a large-current type battery.
A nonaqueous electrolyte secondary battery is required to have higher capacity characteristics and output characteristics, etc. (for example, JP-A-2013-149408). As a method of increasing the capacity of a stacked type nonaqueous electrolyte secondary battery, there is a method of increasing the area of each electrode plate by increasing the area of the main plane of the entire battery. In another method, the capacity is increased by increasing the number of stacked plates (by increasing the thickness of the battery) instead of increasing the area of the main plane of the entire battery. However, the former method, in which the battery is thinner, i.e., the battery has a larger area, is superior in point of heat dissipation or the like.